Add healthcheck command

Dockerfile

@@ -5,6 +5,7 @@ COPY go.mod go.sum ./
 RUN go mod download
 COPY . ./
 RUN CGO_ENABLED=0 GOOS=linux go build -o /hats
+RUN CGO_ENABLED=0 GOOS=linux go build -o /healthcheck ./cmd/healthcheck/main.go
 
 FROM builder as tester
 
@@ -13,4 +14,5 @@ RUN go test -v
 FROM scratch
 
 COPY --from=builder --chmod=755 /hats /hats
+COPY --from=builder --chmod=755 /healthcheck /healthcheck
 ENTRYPOINT [ "/hats" ]

cmd/healthcheck/main.go

@@ -0,0 +1,22 @@
+package main
+
+import (
+	"os"
+
+	"github.com/go-resty/resty/v2"
+)
+
+func main() {
+	c := resty.New()
+	resp, err := c.R().Get("http://127.0.0.1:8888/status")
+
+	if err != nil || !resp.IsSuccess() {
+		os.Exit(1)
+	}
+
+	if string(resp.Body()) == "OK" {
+		os.Exit(0)
+	}
+
+	os.Exit(1)
+}